Portable enclosures, such as tents, have been used as blinds and shelters since the beginning of recorded time. The structure and appearance of such enclosures is as varied as human culture.
More recently, portable, lightweight, durable, and affordable enclosures have become a desirable accessory for many outdoor recreational activities, including camping and hunting. The widespread availability of modern lightweight structures and fabrics has resulted in the proliferation of literally hundreds of new designs for portable enclosures. Among the many popular current styles for tents and hunting blinds are the so-called “collapsible” structures that utilize a spring-like framework that can be easily collapsed and folded for transportation and storage. Such popular designs are typified in, for example, our current and co-pending application Ser. No. 10/025,279.
These types of enclosures are inexpensive, lightweight, and convenient to use. However, one drawback in structures of this type is found in the lack of support available for the roof or upper portion of the enclosure. Early designs used the tension created by the pull of the side panels against the top fabric, but the tension applied to the top fabric was limited. Over time, the fabric of the enclosure stretches, and the framework elements lose their resiliency. Eventually, the roof or top portion of the enclosure sags and deforms, restricting head room inside the enclosure and allowing the collection of water and debris on the roof area. In addition, the relaxation of fabric throughout the structure causes an overall loss of rigidity throughout the structure over time.
It is desirable, therefore, to improve the structural integrity of existing collapsible structures by inclusion of lightweight and resilient frame elements that can be easily transported, inserted in the structure of the enclosure and removed with a minimum of difficulty, and that can be easily adapted to cause the roof or upper portion of the enclosure to conform to a particular profile, thereby elevating or extending a portion of the enclosure upward.